Pump plunger



S. H. HOLT PUMP PLUNGER Get. 8, N46.

Filed Feb. 22, 1945 I INVENTOR.

A3,., ai rroe/wsrs.

Patented Oct. 8, 19u46 PUMP PLUNGER Y,

Sherman H. Holt, Tulsa, Okla. y Application February 22, 1945, Serial No. 579,263.

3 Claims. (o1. 30s-.4)

This invention relates'to oil well pump plungers. v In one kind of oil well pump a pump barrel is lowered into a well and locked in position, and a hollow plunger connected to the lower end of a pump rod is reciprocated in the barrel to pump the oil to the surface. In the inverted type pump the lower end of a hollow plunger is locked in .the well and a barrel encircling the plunger is reciprocated thereon by means of a pump rod. In either case the plunger has a vertical ltubular body surrounded by one or more packing members. One packing member generally is wound around the tube in the form of a coil with one end resting against a stationary member on the tube while the other end engages a packing follower or collar slidably mounted on the tube. On the opposite side of the collar there are one or more packing cups each engaged by a metal cup ring alsol slidably mounted on the plunger body. The outer ring is engaged by a coil spring which -is held in position by a. stationary member on .the plunger tube. This spring urges the cup rings and packing cups toward the collar ywhich in turn presses against the helical packing coil to keep it expanded against the barrel in which the plunger is mounted. The pressure of the fluid in the well on the packing cups also tends to hold the collar .tightly against .the packing. On the downstroke of .the plunger in an ordinary pump, or on the downstroke Iof .the barrel in an inverted pump, the frictional engagement of .the barrel with .the packing cups tends to move them and .the cups rings and collar away from the helical packing, compressing the spring somewhat in doing so. On the reverse stroke these slidable members all move back to their original positions. 'I'his constant travel back and forth tends to create wear on both the packing coil and the packing cups as well as on the spring.

It is among the objects of this invention to provide an oil well pump plunger in which the packing 4cups and packing follower are restrained from being moved `away from the packing coil by friction between the pump barrel and packing cups, and in which this result is accomplished without interfering with the tendency of the plunger spring to keep the packing follower pressed tightly against the packing coil.

The preferred embodiment of this invention is illustrated in the accompanying drawing in which Fig. 1 is a side view, with the barrel and valves partly broken away in section, of an inverted rod pump incorporating my invention, Fig. 2 is an enlarged fragmentary View showing the position of certain plunger elements during a downstroke r 2 of the barrel, and Eig. 3 is a` vertical section through Fig. 2.

Referring to Fig.v 1 of the drawing, a hollow vertical plunger lI is rigidly mounted on the upper end of a conventional hold-down 2 by which the 4plunger is held down in an oil well. This holddown inc ludesl an upwardly opening ball check vali/e3. Slidably mounted on the plunger is a .cylindrical pump barrel 4 which includes at its upper end an upwardly opening ball check valve 5. The top of the barrel is provided with a :threaded stud 6 to which the lower end vof a reciprocable pump rod (not shown) can be attached for moving the barrel .up and down on 4the stationary plunger. This causes the fluid below the pump to be drawn up through the hold-down and hollow plunger into the barrellv and then Ito be forced out of the top of the barrel above the upper valve 5.

The body of the plunger is a vertical tube 8 (Fig. 2) having an lintegral enlargement 9 near its lower end and against the bottom of which an annular centering member I0 is held by a coupling II screwed part way onto the tube. This v coupling is :connected by a pipe I2 to the top of bottom valve 3, whereby .there is a vertical passage from .the lower end of Ithe hold-down .to the top of the plunger. Screwed on the upper end of the tube is a pair of nuts I4 and I5 between which there is a centering member I6. The two centering members center the plunger in the barrel.

Mounted on the plunger tube between lower nut I5 and enlargement 9 is .the packing by which uid is prevented from escaping past the outside of the plunger. The main packing consists of a length of suitable packing material wrapped helically in a coil I8 around the plunger tube with its upper end engaging nut I5. The lower end of .this .coil is engaged by a follower or collar I9 slidably mounted on the tube. Engaging the bottom of the collar is a packing cup 20 into which .projects the reduced upper end of a metal cup ring 2|. The bottom of this ring is engaged by another packing cup 22 into which projects the reduced upper end of another cup ring 23. Both cups and rings are slidably mounted on the plunger tube. Of course, more :cups and rings may be used if desired, and some may be located below enlargement 9. Below the lower ring a coil spring 24 is mounted on the tube with its lower end abutting against tube enlargement 9. 'I'he purpose of this spring is to hold the packing .cups in position and -to keep collar I 9 pressing upwardly against the packing coil I8 so that the coil will be maintained expanded radially into between the upper end of the spring and the Accordingly, a, backingring 2,6 is slidably mounted on thetube.

lower cup ring. both of which it engages. One of these two adjoining rings 23 and 26 has its s l surface which is at the end adjacent the other ring inclined to the axis of the tube and to the ring face it engages. Because it is desirable to make the backing ring thin, it is preferred that the lower face 21 of cup ring 23 be inclined or beveled. This ring therefore engages the back# ing ring only at one side of the plunger tube. This does not keep the spring from performing its function of constantly urging the rings, packing-cups, and collar upwardly on the plunger tube. However, on the downstroke ofthe barrelwhenits friction against thepacking cups at'- tempts to move them downwardly ontlie plunger tube, lower cup ring 23 is caused to exert pressure on the backing ring at only one side of the tube, whereby the thin ring is canted or cockedon the tube as shown in Fig. 2. The backing ring therefore binds on the tube and refuses to slide downwardly on it. The result is that the packing cups and the other slidable members on the.

plunger tube are 4prevented from alternately moving `down and up on Athe tube which 'would cause them-to wear an undesirable amount.

According Ato the provisions of the patent statutes, I have explained the principle and construction of my invention and have illustrated' and described what I now consider to represent its best embodiment. However, I desire to -liave it understood'that, within'the scope of the appended claims, lthe invention may be practiced otherwise than as specifically illustrated and described. Y

I claim:

Vably mounted on said tube in 1. A plunger comprising a vertical tubular body, a, packing cup slidably mounted on said body, a cup ring slidably mounted on said body in engagement with said cup, a backing ring slidably mounted on said body in engagement with the cup ring, and a spring mounted on said body and urging said rings toward the cup, one of said rings having its end face which is adjacentlthe other ring inclined to its axis, whereby anyQten'dency ofthe packing cupto move the rings axially and compress the spring will cant the backing ring into binding engagement with said body and prevent such movement.

2. A plunger comprising a vertical tubular body, a packing cup slidably mounted on said body, a cup ring slidably mounted on said body 'in engagement with said cup, a backing ring slidably mounted on said body in engagement with the cup ring, and a spring mounted on said body and urging said rings toward the cup, the cup ring -havingits end face which is adjacent thev backing Vring inclined to thev backing-ring face that it engages, whereby any tendency of j the packing cup to move the rings axially and, compress the spring will cant the backing ring into vbinding engagement with said body and prevent such movement. 1 3. A plunger comprising a vertical tube, 'a' helical packing member wound on saidtube. means rigidly mounted on said tube'again'st onel end of said packing, a, collar slidably mountedi on said tube against the other end of said packing, a packing cup slidably mounted on said tube'l on the other side of said collar, a cup ring' slid-A engagement with" said cup, a thin backing ring slidably mountedf on said tube in engagement with the cup':ring and a coil spring mounted on said tube and urg` 4 ing said rings and cup toward said collar, the loup* ring having its end face which is adjacentthelj backing ring inclined to its axis, whereby-any1* tendency of the packing cup to move the'A rings'- axially and compress the spring will cant the4 backing ringinto binding-engagement with said body and prevent such movement. f SHERMAN H. 4HC )I' I.V j l 

